I have one script running on server and doing some job on other server
I have many scp commands and ssh commands, this is why each time I have to enter the remote server password at each remote command.
is there any way to establish ssh connection between the servers so I type the remote password only once?
thanks
I would suggest to setup an ssh config together with ssh keys. In a nutshell the config will hold an alias for one or more remote servers.
ssh remote_server1
ssh remote server2
While your config file will look something like this:
Host remote_server1
Hostname 192.168.1.12
user elmo
IdentityFile ~/.ssh/keys/remote.key
...
If an ssh config file is not for you (although I can highly recommend it), you can use sshpass as well.
sshpass -p 't#uyM59bQ' ssh username#server.example.com
Do note that the above does expose your password. If someone else has access to your account, the history command will show the code snippet above.
Related
The situation is that my client machine does not use static IP but the server machine is using static IP.
I connect to the server machine using ssh from the client machine.
Are there any easy ways to send files from the server machine to the client machine using scp or other commands?
I want to execute commands inside the server.
You can scp from the client machine and get the file from the server.
client$ scp user#server:< path to file > < path to destination folder in client >
eg, if you want file1 in the home directory from the server copied to the current directory in your client, you can do the following:
$ scp user#server:~/file1 .
ref: https://linuxize.com/post/how-to-use-scp-command-to-securely-transfer-files/
If you don't really need to connect using the ssh command, you can connect using the sftp command (ftp-like interface through an ssh connection):
$ sftp user#server
And then just use the command get:
sftp> get <file>
Commands like ls, cd and pwd also work in this sftp interface.
I am creating a bash script that trying to connect to a remote server, but it requires to enter a password, I wrote the following script:
ssh HostIP
expect "password:"
send "password"
but it connects and gives "user#HostIP's password:", so the send command is not writing any password to the screen....what should I do to make it work?
Writing passwords in file(s) or scripts is NEVER a good practice. Why don't you give a try to password less authentication from one server to another.
Simple steps:
I- generate the RSA public and private keys from command ssh -keygen -t rsa to your server1.
II- Now create .ssh directory in your another server(server2)'s home dorectory with correct permissions.
III- Create file named authorized_keys on server2.
IV- Open file named authorized_keys on server2 and copy file named id_rsa.pub from server1 to server2.
V- Set permissions to 640 to ~/.ssh/authorized_keys now.
VI- try to login to server2 now by doing:
ssh user#server2
Here is a nice link which could tell you about same too.
https://www.tecmint.com/ssh-passwordless-login-using-ssh-keygen-in-5-easy-steps/
Once passwordless authentication is set from server1 to server2 with ssh then you could simply execute all ssh commands in your script which you want to run on another server.
You can do it with sshpass like :
sshpass -p **your_password** ssh user#HostIP
If sshpass is not already installed, you can install it and make the first connection in bash console for "the yes confirmation"
Perhaps the answer to this question is that it is not possible but hopefully someone knows how to get around this issue. In the past, before the admins configured Kerberos in our school machines I was able to create ssh keys for several purposes. The way this was done was via the ~/.ssh/config file in my machine and the ~/.ssh/authorized_keys in the server. An example of my ssh config file goes as follows
Host sayHI
IdentityFile path/to/sayHiPrivateKey
HostName servername
User myusername
Host sayHey
IdentityFile path/to/sayHeyPrivateKey
HostName servername
User myusername
Then in the authorized_keys file I would have
command="echo hi" ssh-rsa sayHiPublicKeyLONGSTRING....
command="echo hey" ssh-rsa sayHeyPublicKeyLONGSTRING....
ssh-rsa otherkeysformypasswordlessentry
With this setup I could do something like
$ ssh sayHI
hi
$ ssh sayHey
hey
Unfortunately, this has now stopped since we are now using Kerberos to authenticate every day. What this means is that now I have do
$ kinit username#SERVERNAME
Once I put in my password I can use ssh as follows:
$ ssh -K username#hostname
and now I have access. If I do
$ ssh sayHi
this will not work since it asks for my password. If I do
$ ssh -K sayHi
this logs me in but it completely ignores the fact that this was supposed to use an identity so that I can run the command echo hi. Instead it just uses the kerberos credentials and logs me in. So now that I have explain the functionality that I once had, does anyone know if it is possible to recover this using kerberos and ssh? The multiple identities files was useful specially if you wanted to let a friend run a command on your behalf without giving them your password (http://docstore.mik.ua/orelly/networking_2ndEd/ssh/ch08_02.htm). I really hope this is still possible somehow. Thanks in advance.
It depends if the server still accepts pubkey authentication or not (it looks like it does not, otherwise the kerberos authentication wouldn't make any sense).
Depending on the vendor of the OS, there might be possible to set up .k5login, but it will probably not solve the issue. Better way to differentiate between the commands would be using some alias on your client:
alias sayHi="ssh -K host echo Hi"
alias sayHello="ssh -K host echo Hello"
in your ~/.bashrc.
I want to transfer some files from my local to remote, like github does it. I want to happend it very smooth like in shell script. I tried creating one shell script which automates the process of ssh authentication without password but for first time it exposes my remote server password. I dont want to do it that way. Like in git we can't see their server password. Is there any possible way that we can do ?
I used this article script to automate ssh login. http://www.techpaste.com/2013/04/shell-script-automate-ssh-key-transfer-hosts-linux/
As i mentioned, you can use the scp command, like this:
scp /local_dir/some*.xml remote_user#remote_machine:/var/www/html
This requires that you need connect to the remote machine without password, only with ssh key-authentication.
Here is a link: http://linuxproblem.org/art_9.html to help you.
The important steps: (automatic login from host A / user a to Host B / user b.)
a#A:~> ssh-keygen -t rsa
a#A:~> ssh b#B mkdir -p .ssh
a#A:~> cat .ssh/id_rsa.pub | ssh b#B 'cat >> .ssh/authorized_keys'
I need to execute shell script on my remote linux machine. Do you know any tools that can help me doing that?
Thanks,
You can connect through ssh passing a command as a parameter:
ssh user#remote.ip.address "~/myscript.sh"
To connect without password, use ssh keys. To use keys, you have to generate a pair at your machine, with the command:
ssh-keygen
Then take the contents of the file ~/.ssh/id_rsa.pub (or id_dsa.pub if you use parameter -t dsa in ssh-keygen) and put in the file ~/.ssh/authorized_keys of the remote_machine. The .ssh dir must have permission 700.
For Python you can use Paramiko to run commands on the remote computer over SSH.
Passwordless remote execution without waiting for remote script to complete before terminating the ssh connection:
ssh -i ~/.ssh/id_rsa user#remote nohup sh /path/to/script.sh > /dev/null 2>&1 &
If you want to execute a local script on remote host
ssh remotePassword#remoteHost < localScript.sh
If you want to invoke a script on remote host
ssh remotePassword#remoteHost "remoteScript.sh"